#include <stdio.h>
#include <signal.h>

void sigcallback(int signum)
{
    printf("signum %d\n", signum);
}

int main()
{
    //typedef void (*sighandler_t)(int);
    //sighandler_t signal(int signum, sighandler_t handler);
    signal(9, sigcallback);

    while(1)
    {
        ;
    }
    
    return 0;
}
